Biphenyl imidazoles and related compounds of Formula I, useful as antiviral agents, are provided herein. Pharmaceutical compositions containing a compound of Formula I, together with a second active agent, such as an NS3a protease inhibitor are provided herein. Methods for treating viral infections, including Hepatitis C infections, are included herein by providing a compound of Formula I together with an additional active agent. In certain embodiments the additional active agent is an NS3a protease inhibitor.